010:“implements Runnable” vs. “extends Thread”？

Posted 2022-12-07 氵冫丶

题目：“implements Runnable” vs. “extends Thread”？

具体实现方式如下程序

public class stackoverFlow 

    public static void main(String[] args) 
        new MyThread().start();
        new MyThread().start();
        new MyThread().start();

        System.out.println("#######################");
        MyRunnable myRunnable = new MyRunnable();
        new Thread(myRunnable).start();
        new Thread(myRunnable).start();
        new Thread(myRunnable).start();
    


/**
 * 继承 Thread类实现多线程
 *
 */
class MyThread extends Thread 
    public MyThread() 
        super("MyThread");
    
    public void run() 
        for(int i=0;i<10;i++)
            System.out.println("i = " + i +" MyThread "+Thread.currentThread().getName());
        

    


/**
 * 实现Runnable接口实现多线程
 *
 */
class MyRunnable implements Runnable
    public void run() 
        for(int i=0;i<10;i++)
            System.out.println("i = " + i +" MyRunnable"+Thread.currentThread().getName());
        
    

测试输出

#######################
i = 0 MyThread MyThread
i = 0 MyThread MyThread
i = 1 MyThread MyThread
i = 2 MyThread MyThread
i = 3 MyThread MyThread
i = 4 MyThread MyThread
i = 5 MyThread MyThread
i = 6 MyThread MyThread
i = 7 MyThread MyThread
i = 8 MyThread MyThread
i = 9 MyThread MyThread
i = 0 MyThread MyThread
i = 1 MyThread MyThread
i = 2 MyThread MyThread
i = 3 MyThread MyThread
i = 4 MyThread MyThread
i = 5 MyThread MyThread
i = 6 MyThread MyThread
i = 7 MyThread MyThread
i = 8 MyThread MyThread
i = 9 MyThread MyThread
i = 1 MyThread MyThread
i = 2 MyThread MyThread
i = 3 MyThread MyThread
i = 4 MyThread MyThread
i = 5 MyThread MyThread
i = 6 MyThread MyThread
i = 7 MyThread MyThread
i = 8 MyThread MyThread
i = 9 MyThread MyThread
i = 0 MyRunnableThread-0
i = 0 MyRunnableThread-2
i = 1 MyRunnableThread-2
i = 2 MyRunnableThread-2
i = 3 MyRunnableThread-2
i = 4 MyRunnableThread-2
i = 5 MyRunnableThread-2
i = 6 MyRunnableThread-2
i = 7 MyRunnableThread-2
i = 8 MyRunnableThread-2
i = 0 MyRunnableThread-1
i = 1 MyRunnableThread-1
i = 2 MyRunnableThread-1
i = 3 MyRunnableThread-1
i = 4 MyRunnableThread-1
i = 5 MyRunnableThread-1
i = 6 MyRunnableThread-1
i = 7 MyRunnableThread-1
i = 8 MyRunnableThread-1
i = 9 MyRunnableThread-1
i = 1 MyRunnableThread-0
i = 9 MyRunnableThread-2
i = 2 MyRunnableThread-0
i = 3 MyRunnableThread-0
i = 4 MyRunnableThread-0
i = 5 MyRunnableThread-0
i = 6 MyRunnableThread-0
i = 7 MyRunnableThread-0
i = 8 MyRunnableThread-0
i = 9 MyRunnableThread-0

关系图

可以看出
Runnable可以避免由于java的单继承机制带来的局限。可以再继承其他类的同时，还能实现多线程的功能

本专题来源stackoverflow 标签是java的投票数比较高的问题以及回答，我只对上面的回答根据自己的理解做下总结。